Oil in bellows

[salty3rd]

Gents,
Pulled my Bravo 3 off last week and found some fluid in the gimbal housing bellows. My first thought was that it was gear lube from the drive. This fluids consistency and smell does not seem like the Mercruiser gear lube that’s in the drive, and I never had to add any lube to the resovior last season. Is it possible this could be water mixed with some residual grease inside the bellows? No rust or corrosion on gimbal bearing, drive shaft or u joints that you would expect to see with a leaking bellows. Any other ideas? Or is my first guess about a drive leak valid? Thanks for everyone’s help.

 

[Scott Danforth]

pressure test the drive. most likely the input seal is bad

 

[dubs283]

is my first guess about a drive leak valid?

Possible, as mentioned a pressure test can reveal a leak at the yoke seal which would account for the issue but ime a small amount like in your picture doesn't often result in the yoke seal failing a pressure test. Not to say passing a pressure test rules out the yoke seal but the nature of pressure testing a drive doesn't always reveal an issue due to the lack of load on the drive/components. Best one can do is simulate load by rotating the input shaft by hand and manually shifting the drive during testing

Gear oil when old, burnt, dirty, etc...has a distinct, strong odor. Plus high performance (guessing you're using that) is a blue/green color when new and normally turns darker/black with age. First glance would say to me there is rust in whatever the substance is in the photo

How often do you pull the drive for maintenance/inspection?

 

[Scott06]

These guys have you steered straight. Pressure test the drive to see if input shaft is leaking. Gear lube is pretty unique in smell... were you loosing lube in the bottle last year ? Some liquid will come out of the grease in the gimbal bearing and end up in bellows too. If drive pressure tests ok it is likely from the grease

 

[salty3rd]

Possible, as mentioned a pressure test can reveal a leak at the yoke seal which would account for the issue but ime a small amount like in your picture doesn't often result in the yoke seal failing a pressure test. Not to say passing a pressure test rules out the yoke seal but the nature of pressure testing a drive doesn't always reveal an issue due to the lack of load on the drive/components. Best one can do is simulate load by rotating the input shaft by hand and manually shifting the drive during testing

Gear oil when old, burnt, dirty, etc...has a distinct, strong odor. Plus high performance (guessing you're using that) is a blue/green color when new and normally turns darker/black with age. First glance would say to me there is rust in whatever the substance is in the photo

How often do you pull the drive for maintenance/inspection?

Yes using the blue high performance gear lube. Like I said, the substance doesn’t smell like gear lube to me.

I agree it looks like rust in the picture, but here is a photo after I wiped the gimbal bearing, no rust on it or the drive shaft. I pull the drive every Spring for maintenance and inspection.

 

[salty3rd]

These guys have you steered straight. Pressure test the drive to see if input shaft is leaking. Gear lube is pretty unique in smell... were you loosing lube in the bottle last year ? Some liquid will come out of the grease in the gimbal bearing and end up in bellows too. If drive pressure tests ok it is likely from the grease

I agree it is unique in smell, and that’s why I’m concerned that this substance doesn’t smell or feel like gear lube. I wasn’t loosing gear lube last year. Would the grease coming out of the gimbal bearing amount to as much as is in the pictures?

 

[Scott Danforth]

It's gear oil and water mixed